Securities - Amortized Cost and Fair Value (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Securities Available-for-Sale
Amortized Cost	$ 404,429	$ 391,694
Gross Unrealized Gains	432	1,147
Gross Unrealized Losses	(5,609)	(7,355)
Fair Value	399,252us-gaap_AvailableForSaleSecurities	385,486us-gaap_AvailableForSaleSecurities
Securities Held-to-Maturity
Amortized Cost	257,332us-gaap_HeldToMaturitySecurities	259,670us-gaap_HeldToMaturitySecurities
Gross Unrealized Gains	8,023	5,035
Gross Unrealized Losses	(260)	(1,439)
Fair Value	265,095	263,266
U.S. Treasury
Securities Available-for-Sale
Amortized Cost	1,524	1,529
Gross Unrealized Gains	1
Gross Unrealized Losses		(2)
Fair Value	1,525	1,527
U.S. government agencies
Securities Available-for-Sale
Amortized Cost	1,704	1,711
Gross Unrealized Losses	(93)	(87)
Fair Value	1,611	1,624
States and political subdivisions
Securities Available-for-Sale
Amortized Cost	33,573	21,682
Gross Unrealized Gains	327	432
Gross Unrealized Losses	(154)	(96)
Fair Value	33,746	22,018
Corporate bonds
Securities Available-for-Sale
Amortized Cost	33,385	31,243
Gross Unrealized Gains	23	309
Gross Unrealized Losses	(404)	(567)
Fair Value	33,004	30,985
Collateralized mortgage obligations
Securities Available-for-Sale
Amortized Cost	69,205	65,728
Gross Unrealized Gains	50	31
Gross Unrealized Losses	(1,162)	(2,132)
Fair Value	68,093	63,627
Securities Held-to-Maturity
Amortized Cost	220,197	222,545
Gross Unrealized Gains	5,482	3,005
Gross Unrealized Losses	(260)	(1,439)
Fair Value	225,419	224,111
Asset-backed securities
Securities Available-for-Sale
Amortized Cost	170,817	175,565
Gross Unrealized Gains	18	199
Gross Unrealized Losses	(2,579)	(2,268)
Fair Value	168,256	173,496
Collateralized loan obligations
Securities Available-for-Sale
Amortized Cost	94,221	94,236
Gross Unrealized Gains	13	176
Gross Unrealized Losses	(1,217)	(2,203)
Fair Value	93,017	92,209
U.S. government agency mortgage-backed
Securities Held-to-Maturity
Amortized Cost	37,135	37,125
Gross Unrealized Gains	2,541	2,030
Fair Value	$ 39,676	$ 39,155

Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

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Amount before tax of unrealized gain in accumulated other comprehensive income (AOCI) on investments in debt and equity securities classified as available-for-sale.

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Amount before tax of unrealized loss in accumulated other comprehensive income (AOCI) on investments in debt and equity securities classified as available-for-sale.

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This item represents the cost of debt and equity securities, which are categorized neither as held-to-maturity nor trading, net of adjustments including accretion, amortization, collection of cash, previous other-than-temporary impairments recognized in earnings (less any cumulative-effect adjustments recognized, as defined), and fair value hedge accounting adjustments, if any.

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Amount after other than temporary impairment (OTTI) accretion, of investments in debt securities classified as held-to-maturity.

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Amount of accumulated unrealized gain on investments in debt securities classified as held-to-maturity.

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Fair value of investments in debt securities classified as held-to-maturity.

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